Carriage orientation and lift system for a twin belt continuous metal casting machine

ABSTRACT

A carriage orientation and lift system are described for a continuous metal casting machine of the twinbelt type in which a virtual parallelogram lift mechanism raises or lowers the upper carriage while maintaining it parallel with the lower carriage. This lift system permits the lower carriage to be rigidly attached to the main chassis frame and back of the machine with a lever lift arm extending over the back to support the upper carriage, this arm being mounted on the back by a fulcrum pivot assembly including adjustment means to align the motion of the upper belt with the lower belt so that they &#39;&#39;&#39;&#39;track&#39;&#39;&#39;&#39; each other precisely along the upper and lower surfaces of the casting region. A follower roller engages an upright curved cylindrical segment on the back of the machine, and the radius of this curved segment plus the radius of the follower roller is equal to the length of the lift arm between the fulcrum and the pivot connection to the upper carriage to provide parellelism of the carriages at all lifted positions. A downstream shift assembly at this pivot connection enables the upper carriage to be shifted upstream or downstream for injection or open pool feeding of the molten metal input to the machine, and the curved cylindrical segment and follower roller facilitate such adjustment, this downstream adjustment being completely independent of the upper carriage lift means and lifting action.

[ Nov. 19, 1974 nited States Patent [191 Hazelett et al. I

[ CARRIAGE ORIENTATION AND LIFT [57] ABSTRACT A carriage orientation and lift system are described for a continuous metal casting machine of the twinbelt type in which a virtual parallelogram lift mechanism raises or lowers the upper carriage while maintaining it parallel with the lower carriage. This lift system pe SYSTEM FOR A TWIN BELT CONTINUOUS m s .m m mm tn 2 M Emm at mm Am wmm G mw r n l nrfl Twhm flRhB mm m m EV M .m 3 7 Colchester, all of Vt.

mlts the lower carriage to be rigidly attached to the linden-Strip main chassis frame and back of the machine with a lever lift arm extending over the back to support the [73] Assignee: Casting Corporation,

y e ley w Cum u dd 6.m rtVa P au cc h mm m w m film hon. m e nm n f k 0 c upper carriage, this arm being mounted on the back by a fulcrum pivot assembly including adjustment means to align the motion of the upper belt with the lower belt so that they along the upper and lower surfa gion. A follower roller engages lindrical segment on the back 2 t 27 V WBZ o mml yw "moo a l w 6 6 WW6 1 H l 9 m. e 0 "u" n r. a n 2 u a a 4 m M M 3 mumm 0 "We N L m C d w m w P mh F A UIF radius of this curved segment plus the radius of the follower roller is equal to the length of the lift arm be- [56] References Cited tween the fulcrum and the pivot connection to the upper carriage to provide parellelism of the carriages UNITED STATES PATENTS at all lifted positions. A downstream shift assembl yat this pivot connection enables the upper carriage to be shifted upstream or downstream for injection or open 64/278 lf d f h 1 l' h h" l64/278 poo ee mgo t emo ten meta input tot emac me,

Hazelett..........................

Hazelett.

Ln t... km ee 22 33 HH 9457 5666 9999 HHHH 9823 0309 6734 4270 046 ll-a3 233 and the curved cylindrical segment and follower roller 'Primar ,Examiner An'drew R Juhasz facilitate such adjustment, this downstream adjust- Assl-smit Examiner john S B'rown ment being completely independent of the upper car- Attorney, Agent, or Firm-Bryan, Parmelee, Johnson g 11ft means and hftmg & Bollinger 15 Claims, 9 Drawing Figures 'SHEEISUF 8 PATENIEL RBV I 9 I974 DESCRIPTION The present invention relates to a carriage orientation and lift system for a twin-belt continuous metal casting machine. Such a twin-belt casting machine uses a pair of thin, wide endless metal belts to define the upper and lower casting surfaces of the casting region.

These belts are revolved around cantilevered upper and lower carriages. Separation of these carriages is necessary from time to time to replace these casting belts, or to change the edge dams and provide access for servicing the carriages and rolls and to make periodic inspections.

There have been earlier twin-belt continuous metal casting machines, for example, as shown in US. Pat. Nos. 2,640,235; 2,904,860; 3,036,348; 3,041,686; 3,123,874; 3,142,873; 3,167,830; 3,228,072; and 3,310,849. As time has passed, the operating requirements for these twin-belt casting machines have become progressively more demanding because it is desired that larger and larger cast sections be produced with great accuracy. Thus, much larger amounts of molten metal are now desired to'be fed into the machine per minute of operation.

Among the many advantages of the present invention are those resulting from the fact that very wide, large casting belt carriages can be positioned in precise parallel relationship with respect to each other, and the upper carriage can be raised a substantial distance while maintaining the parallelism desired. A virtual parallelogram lift system that raises the upper carriage is provided to accomplish the desired separation of the carriages, and also it permits rigidly attaching the lower carriage to the main chassis frame without complication or conflict with other functions. A follower roller engages against an upright, curved cylindrical segment on the back of the machine and the radius of curvature of this curved segment plus the radius of the follower roller is equal to the length of the lift arm between the fulcrum and the pivot connection to the upper carriage. Thus, parallelism is maintained without the complexity of a fourth movable link and associated pivots. A substantial amount of vertical lift is thereby provided for the installation and removal of large casting belts on machines with large mold dimensions. For example, the illustrated embodiment is designed to provide a casting mold space C which may be as wide as up to 100 inches and may be as long as up to 1 16 inches or more, with the belts being somewhat larger than these dimensions.

Substantial vertical lift of the upper carriage also facilitates the changing of casting belts, edge dams, tundish, nosepiece and nozzle assemblies on various sizes of casting machines in installations where down time vide vertical support for the upper carriage, and control the distance between the two carriages.

Accordingly, another important advantage of the lift system embodying this invention is that the upper carriage and corresponding casting surface remain parallel with the lower carriage while being raised or lowered. This facilitates the changing of selected casting thickness together with corresponding edge dams and gauge spacers. Maintaining the upper carriage parallel to the lower carriage during operation of the lift function also allows the upper carriage to be used to position tundish, nosepiece or core assemblies. Desirably, a lift system embodying the present invention that maintains the constant parallel position of the upper carriage can be used as well to actuate the head latch and raise the leveler or other auxiliary assemblies when the lift system is operated.

In certain prior twin-belt machines, it has been desirable to isolate the lower carriage from the base frame. For example, US. Pat. No. 3,142,873 shows a system for isolating the lower carriage from the base frame. Thus, any distortion of the base due to unexpected loads or foundation problems did not distort the lower carriage. In a machine embodying the present inven tion the lower carriage is rigidly attached to a main chassis which is pivoted to the base frame but this chassis also carries a heavy upright box frame forming the whole back of the machine so that the back frame of the machine, the main chassis, and the lower carriage are rigidly interconnected to provide great strength and rigidity.

It is a further advantage of a machine embodying the present invention thatadjustment means are provided at the fulcrum of the virtual'parallelogram lift system to align the upper and lower carriages so that the direction of travel of the two belts is exactly parallel along y the top and bottom surfaces of the casting region C. This precise parallelism, i.e. tracking of the two belts, is required to assure that there is no lateral creeping movement between either of the belts and the section of molten metal being cast. Such lateral creeping movement if it occurs can drastically reduce the life of the casting belt coating and produce flaws in the surface finish of the cast section. The virtual parallelogram lift system eliminates a link and two pivots, thus providing additional space for other functions. In addition,

the absence of such a link and associated pivots enables the adjustment means at the fulcrum of the lift arm to produce tracking of the two belts without further links or pivots to be adjusted.

For optimum flexibility in use, the area above the upper carriage is desirably open sothat auxiliary equipment such as belt drying or coating apparatus can be mounted there. To provide for both injection and open pool feeding of the molten metal, a meansfor shifting the upper carriage in the direction of travel of casting is provided. For open pool feeding the upper carriage is shifted downstream a substantial distance. This shift A function is independent of all other machine operations. The virtual parallelogram lift system facilitates this downstream shifting by eliminating pivots which might otherwise require shifting. The curved segment against which the follower roller rests is much wider than the roller thereby accommodating all downstream shifts of the upper carriage.

A positive safety link is provided to positively lock and hold the upper carriage in the raised position to present invention will be more fully understood from a consideration of the following description of a twin-belt continuous metal casting machine incorporating the invention, considered in conjunction with the accom' panying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the input or upstream end of a continuous strip-casting machine embodying the present invention, as seen looking toward the machine from a position in front and beyond the outboard side of the two belt carriages;

FIG. 2 is an elevational view of the machine as seen looking toward the outboard sides of the two belt carriages;

FIG. 3 is an elevational view of the machine as seen looking toward the back of the support frame at the inboard side of the machine;

FIG. 4 is an elevational view looking toward the input or upstream end of the continuous casting machine;

FIG. 5 is a cross-sectional view, taken along the line 5--5 of FIG. 2, looking toward the right;

FIG. 6 is a schematic diagram illustrating the virtual parallelogram linkage provided by the lift system in the machine of the present invention;

FIG. 7 is a perspective view of the upper carriage shift system;

FIG. 8 is an enlarged sectional view of the roller and mount, being taken along line 8-8 of FIG. 4; and

FIG. 9 is an enlarged sectional view of the lift arm bearing and mounting assembly, being taken along line 9-9 in FIG. 4.

DETAILED DESCRIPTION In the continuous casting machine 10, which is shown in the drawings as an illustrative example of the present invention, molten metal is fed into the upstream end or input of the machine between upper and lower endless, flexible casting belts l2 and 14. The molten metal is solidified in a casting region C (FIGS. 2 and 5) defined by the spaced parallel surfaces of the upper and lower casting belts l2 and 14.

The two casting belts 12 and 14 are supported and driven by means of upper and lower belt carriages which are indicated in FIGS. 1, 2 and 4 at U and L, respectively. The upper carriage includes two main rolls 16 and 18 (FIG. 2) around which the casting belt 12 is revolved as indicated by the arrows. The roll 16 near the input end of the machine is referred to as the upstream roll and the other roll 18 is called the downstream roll. Similarly, the lower carriage L includes main upstream and downstream rolls 20 and 22 around which the lower casting belt 14 is revolved.

The lower carriage L projects from a chassis 24 (FIGS. 2 and 4) which is adapted to be tilted to various casting angles. In order to provide for the adjustable tilting of this chassis 24, it is attached to the base 26 of the machine by a three-point support system that includes two pivot connections and an adjusting link 27. The two pivot connections 28 and 30 are located toward the downstream end of the machine, and the adjusting link 27 is near the upstream end. This link is secured by pivots 31 and 32 and can be removed and replaced by a longer link when it is desired to increase the inclination, and vice versa.

As shown in FIGS. 1, 2 and 3, the base 26 and a pair of spaced horizontally extending parallel base beams 34 and 36 bolt together to form an integral, horizontal support unit B for the remainder of the machine. This support B is generally U-shaped in plan, with the two base beams 34 and 36 extending in an outboard direction beneath the lower carriage L. The chassis frame 24 is attached to the base 26 by the pivot system discussed above that allows the carriages U and L to be tilted to any casting angle and still remain in alignment with the base 26. This chassis frame 24 forms the main chassis of the machine proper as distinguished from the support unit B at the base.

A rigid upstanding box frame back 38 is securely bolted to the upper surface of the chassis 24. This box frame back 38 provides the upright back of the machine, and at its upper end there are two upstanding lift arm support members 41 and 43 which support a lift arm 40 at its fulcrum point 42 (FIG. 5) by means of pivot pin assemblies. As shown in FIG. 5, this box frame back 38 includes vertical front and back plates 44 and 45 with horizontal stiffeners 46 between them and a pair of vertical end plates 47 and 48 (FIGS. 2 and 3) to which the upstanding lift arm support members 41 and 43 are secured. The lift arm 40 is swung up and down by the action of the two fluid power cylinders 50 and 51 whose piston rods 52 are pivotally attached at 53 to brackets 54 secured to the rear plate 45 of the box frame back 38. The cylinders 50 and 51 have trunnions 55 pivotally mounted in the rearwardly extending end members 56 of the lift arm 40. The upper carriage U is pivotally attached to the front end of the lift arm 40 by the downstream shift assembly 61, which is located at the outboard end of the lift arm 40.

This lift arm is strongly built to have a thicker section near the fulcrum pivot 42 tapering toward its ends, and it includes a top plate 57 secured to bottom plates 58 and 59 by vertical webs between them, as seen in FIG. 5.

In order to raise and lower the upper carriage U while controlling its orientation to remain parallel with the lower carriage L, a virtual parallelogram lift system 60 has been devised as shown most clearly in FIGS. 5 and 6. The box frame back 38 of the machine forms one link 1 of the parallelogram pivoted at 42 to a central portion of the lift arm 40, and the front portion of this lift arm forms a second link 2. The upper carriage U includes an inboard vertical frame structure 62 which depends from the pivot shift assembly 61, and then as shown generally at 63 in FIG. 6 the belt supporting portion is cantilevered from the upright portion 62. Thus, as seen in cross section in FIGS. 5 and 6, the upper carriage has an L-shape or dog-leg shape.

The third link 3 is formed by the upright dog-leg portion 62 of the upper carriage on which bracket members 66, 67 (FIG. 8) and roller 65 are mounted.

The fourth link 4 is a virtual one as indicated dashed in FIG. 6 with the other two pivots X and Y being virtual pivots. These are called virtual pivots because there is no actual pivot connection between a pair of links at the pivot points X and Y. This virtual fourth link and pivots X and Y are provided by a convex circularly curved cylindrical segment 64 bolted to the front plate of the upright box frame back 38 and a follower roller 65 attached by mounting bracket members 66 and 67 (FIG. 8) to the inboard side plate 68 of the vertical frame structure 62 of the upper carriage. The roller 65 is mounted on the upper carriage U near the elbow of its L-shaped frame structure formed by the upright frame portion 62 and cantilevered belt supporting portion 63.

The radius of the convex curved cylindrical segment 64 plus the radius of the roller 65 are equal to the distance between the axes of the pivots 42 and 61 in the front portion of the lift arm, i.e., equal to the length of the upper link 2. The axis, i.e. center of curvature, of the cylindrical segment 64 is located at the virtual pivot X and extends parallel with the axis of the pivot assembly 61 and also parallel with the axis of the fulcrum pivot 42 which is also parallel to the pivot assembly 61. In addition, the distance from the axis X to the axis of the pivot 42 (which is the length of the link 1) is equal to the distance between the axis Y of the roller 65 and the axis of the pivot 61 (which is the length of the link 3).

Although an exactly circular cylindrical curved segment 64 is shown, it is to be understood that it is possible to use a segment 64 having a surface which approximates this desired shape in order to save machining costs. The reason such an approximation is possible is that the upper carriage rests upon gauge blocks on the lower carriage which control its final precise position when it is fully lowered into operating position with respect to the lower carriage. Accordingly, the circularly curved cylindrical segment is to be interpreted to include approximations thereof.

As mentioned above, the upper carriage U has an L- shaped cantilevered structure 63 carried by the upright dog-leg portion 62, and the weight of this upper carriage when lifted is supportedby the pivot assembly connection 61 with the lift arm 40 and whose orientation about this pivot 61 is controlled by the action of the roller 65 and cylindrical segment 64. As the upper carriage U is raised or lowered, the center line (axis) of its pivot 61 with the lift arm 40 travels in a circular path V about the axis of the lift arm fulcrum pivot 42. In order for the upper carriage U to remain parallel with the lower carriage L, the center line of the foller 65 is arranged to travel in an identical arc W, and this is accomplished by making the radius of the cylindrical segment 64 plus the radius of the roller 65 equal to the length of the link 2.

During operation of the lift system, the roller 65 is under a compressive load and follows the precisely curved machined surface of the segment 64, thus producing the desired parallelogram motion. It is the side portion of the arc W which is used which enables a large amount of vertical movement to be obtained with little horizontal displacement of the upper carriage U. In other words, as shown in FIG. 4, a tangent plane 70 (shown dash and dotted) to the curved cylindrical segment 64 near the center of the operating range extends vertically.

In order to position the curved segment 64 precisely on the vertical front plate 44, there is a horizontal locator bar '72 (FIG. 4) which extends across beneath the bottom end of the curved segment 64, i.e. serving as a ledger. Cap screws (not shown) retain the ledger bar 72 in position on the front surface of the upright box frame back 38. This bar 72 also facilitates the positioning of plate 73 behind the segment 64 both of which are securely fastened to the box frame'38 by cap screws. This spacer plate 73 is mounted between the segment 64 and the box frame back 38 and can be machined to correct any minor misalignment, thus assuring proper contact at all operating positions between the segment 64 and the roller 65. The curved segment is wide enough so that there is full contact with the roller for all downstream shift positions of the upper carriage U, even including the maximum amount of downstream shift of this upper carriage. The hardness of the curved surface of the segment 64 is somewhat less than that of the roller 65 to produce ideal operating conditions at the point of contact. Also, this relative hardness accommodates manufacturing tolerances and adjustments in orientation of the upper carriage.

The roller 65 (FIG. 8) is the outer portion of an anti friction bearing whose inner race 74 is retained between bracket members 66 and 67 by retainers 75 which are compressed between a shoulder 76 on one end of the bearing pin 77 and a bushing 78, a lock washer 79 and lock nut 80 screwed on the opposite end of the pin 77. The bearing for roller 65 includes antifriction elements 81 and is sealed against the ingress of liquid coolant and foreign material on both sides by 0 rings 82 which ride in a groove in the periphery of each retainer 75 and run against the inside surface of the outer race of the bearing which forms the roller 65. This bearing 65, 81, 74 can be lubricated through a passage 82 bored in the retaining pin 77. To insure proper tracking and that there is no lateral motion between the roller 65 and the segment 64, a key 84 (FIG. 5) is used to accurately locate the bracket members 66 and 67 on the inboard side plate 68 of the top carriage. The bracket members 66 and 67 are securely fastened to the side plate with cap screws. This roller means is used to withstand the high operating loads and adverse operating conditions of liquid coolant, heat and fumes encountered during metal casting. In some cases, particularly for a long machine, more than one roller 65 may be utilized in axial alignment with each other engaging the curved surface 64.

The force required to raise the top carriage U is produced by the action of the two fluid power cylinders 50 and 51. As fluid pressure is applied to the rod end of these cylinders, the piston rods 52 are retracted causing a downward force F (FIG. 6) on the rear members 56 of the lift arm 40, thereby swinging the front portion of the lift arm 40 up'about its fulcrum'pivot 42 thus raising the upper carriage U.

Although fluid powered lift cylinders 50 and 51, such as hydraulically activated lift cylinders, are shown as the lift means to exert a downward force on the rear portion of the lift arm 40 by acting between the pivots 53 and 55 (FIGS. 4 and 5), it is to be understood that other lift means can be used. For example, screw jacks can be employed effectively acting between the pivots 53 and 55 with these screw jacks being actuated by electric or hydraulic motors or manually actuatable.

By virture of the provision of the virtual parallelogram described above, the need for an actual link 4 and pivots X and Y is removed, thus there is more room available in the box frame back 38 for other equipment. Also, the elimination of pivots X and Y avoids lubrication and multiple bearing sealing problems.

The lift arm is supported on each side by a fulcrum pivot pin 42 (FIG. 9) about which rotates a bushing 86. This bushing is retained in the box frame back 38 of the machine by a thrust washer 87 and cap 88. An advantage of this rearwardly extending level type lift system 60 is that it can be mounted on the upper portion of the rigid box frame back 38 with the lift arm extending over the top of the box frame back 38. Thus, the top positioned lift arm 40 does not limit the space required for other functions, and the location of the lift means and 51 behind the box frame back 38 enable the lift arm and lift means to withstand adverse operating conditions. This lift system allows the lift means 50 and 51 to be mounted on the back of the machine thus providing more space in the working area and a better environment for the lift cylinders because they are more remote from the molten metal in the casting region C and are remote from the liquid coolant being applied to the reverse surfaces of the belts along the casting region.

The lift arm arrangement as shown in FIG. 5 in which the line of action of the lift means 50 and 51; that is, the line passing through the axes of the pivot points 55 and 53 is approximately perpendicular to the line passing through the pivot points 42 and 53 provides a relatively constant mechanical advantage for the lift cylinders throughout the range of lift operation. This relatively constant mechanical advantage results in substantially constant hydraulic pressure requirements throughout the range of lift. Due to the very limited degree of associated frictional forces, the operation of the lift system is smooth and readily controllable during all phases of the lift cycle. Also, the space above the upper carriage is free of obstruction and can be used to accommodate other mechanism such as the belt treatment unit 85.

In addition to providing support for the lift arm 40, the pivot pin assembly shown in FIG. 9 can be used to adjust the orientation of the lift arm, so that the direction of travel of the top and bottom casting belts is exactly parallel. This is accomplished by the rotation of the bushings 86 which are eccentric in structure. Each cap 88 axially retains the thrust washer 87, bushing 86 and lift arm 40 in position on top of the box frame back 38. The cap 88 is fastened to the vertical members 41 and 43 of the box frame back by cap screws 92 and a lock bolt prevents rotation of the eccentric bushing 86. This eccentric bushing can be rotated in either direction by increments of five degrees, thus providing both horizontal and vertical adjustment of the upper carriage at both its upstream and downstream ends.

There are eight pre-drilled apertures 89 spaced uniformly around the axis of the cap 88, and nine uniformly spaced sockets are pre-drilled in the end face of the bushing 86. Thus, there are a total of 72 possible combinations of apertures 89 and sockets 83 into which the lock bolt 90 can be inserted, hence providing five degree increments of adjustment. The spherical outer surface S (FIG. 9) of each thrust washer 87 accommodates this adjustable orientation of the upper carriage in any direction at both the upstream and downstream fulcrum pivots 42.

In this way, the upper carriage is adjusted to cause its belt to track exactly parallel with the lower belt along the top and bottom of the casting region C; so that the lateral creeping movement of the belts with respect to the cast product is avoided. This true tracking of the belts reduces abrasion on the coated casting surfaces of the belts 12 and 14 and avoids flaws in the surface finish of the cast section. The fulcrum pivot pins 42 and eccentric bushings 86 can be lubricated through the port 91 provided in their respective caps 88 and thrust washers 87. If desired, either or both of the eccentric bushings 86 can conveniently be removed and replaced by one having greater or lesser eccentricity if needed to make a more precise alignment adjustment shown between the upper and lower carriages.

The top carriage U is pivoted on the front portion of the lift arm 40 by the downstream shift assembly 61 and can be moved a maximum of twelve inches independently of all other functions of the casting machine 10. This movement is desirable to allow molten metal to be distributed into the casting region C by either the open pool or injection method.

The main component of the downstream shift assembly 61 is a tube 94 that slides in three bushings 95 that are retained respectively in three spaced hanger members 93 on the front portion of the lift arm 40 by means of snap rings 96. The vertical arm structure 62 of the upper carriage U includes a pair of spaced end plate support members 97 that are rigidly attached to this tube 94 by two rings 98 and a split ring 99. The upstream support member 97 is positioned intermediate the first and second hanger members 93, while the downstream support member 97 is positioned intermediate the second and third hanger members 93 Accord ingly, rigid support is provided for the upper carriage regardless of whether it is shifted upstream, downstream or in-between.

In order to move the main slidable tube 94, there is a larger diameter tubular housing 100 and a spacer 101 bolted to the upstream hanger member 93 of the lift arm 40 concentrically with the main tube 94. A cap 102 is securely fastened to the end of this housing 100 by cap screws. A thrust shaft 104 having screw threads 105 is axially retained in this cap 102 by the action of a pair of thrust bearings 106, spacers 107, lock washer 108 and lock nut 110. The end of this shaft 104 is threaded and screws into a cap 112 which is securely fastened to the end of the main tube 94. When the thrust shaft 104 is turned by applying a wrench to the head end 114, the assembly operates like a screw jack and shifts the top carriage U upstream or downstream with relation to the lift arm 40 and the machine.

The lift system 60 is provided with a positive safety link 116 (FIG. 5) that will retain the upper carriage in the fully raised position. This safety link 116 is manually operable, can be locked in either extended or retracted position, and can be used for all downstream shift positions of the top carriage. While in use, holding up the carriage U, the safety link 116 is in extended position under a compressive load, between a ledge 117 on the top carriage and the pivot 118 of the link 116. In addition, as a back up to the pivot 118, there is a load-carrying ledge 120 at the front of the box frame back 38. The bottom end of the pivoted safety link rests on the safety ledge 120 when the link is swung out to its extended position, so as to catch under the carriage ledge 117. The safety link 116 is located so that it does not interfere with the changing of the casting belts, or any other required maintenance work.

As seen in FIG. 5, there are a pair of edge dams 121 and 122 which serve to define the edges of the casting region C. These edge dams are flexible and revolve around the lower carriage, as seen in FIG. 2. They can be removed and replaced by thicker or thinner ones depending upon the section of metal being cast. These edge dams 121 and 122 and also the casting belts 12 and 14 can be changed when the upper carriage is raised as indicated by the dashed and dotted outline in FIG. 5. Also, inspection and servicing of the machine can be conveniently performed when the upper carriage is raised. It is at these times that the safety link 116 is extended to make sure that the upper carriage does not inadvertently come down. The lift system 60 shown is designed to provide inches of lift for the upper carriage U.

As further provision for controlling carriage orientation, it is noted that the back downstream carriage pivot (FIG. 3) has an associated hold-down clamp including a curved saddle 124 extending over the pivot pin 30 with a clamp bolt 126 and a nut 127. This clamp bolt extends down through an anchoring bracket 129 on the main chassis frame 24 and through the saddle 124 and pivot 30 for securely locking the pivot 30 to remove all tolerance in the pivot. In this way the main chassis frame is pre-loaded (as seen in FIG. 3) down against the base at the downstream back pivot point to prevent any slight movement there.

In addition, the pivot brackets 54 for the lift cylinder piston rods are located on the back frame 38 by keys 128 (FIGS. 4 and 5) in a keyway 130 (FIG. 3) to assure precise alignment.

The belt drive mechanism 132 is mounted upon a platform 134 which is cantilevered from the back of the main chassis 24. Thus, this drive mechanism is positioned in a more favorable environmental position than if it were closer to the casting region. Also, the cantilevered platform 134 and drive 132 somewhat counterbalance the lower carriage L which is rigidly cantilevered from the front of the main chassis 24 with the upper carriage U above it.

As mentioned previously, there is a belt treatment unit 85 (FIGS. 1, 2 and 4) positioned in the readily accessible space above the upper carriage. This belt treatment unit extends across the width of the upper casting belt 12 as seen in FIG. 4 and is used to perform such belt treatments as leveling or coating. In its operating position as seen in FIG. 4 a pivoted latch 136 has a hook 137 engaged in a recess on the frame of the upper carriage. A spring 138 urges the latch into its engaged position about the latch pivot 139. In order to disengage the latch and raise the treatment unit 85, there is a tension member 140, for example, such as a rod or cable, pivotally connected at 141 to the upper end of the latch and at 142 to the front portion of the lift arm above the level of the pivot 61. Thus, when the lift arm is swung up about the fulcrum pivot 42, the initial part of this upward motion pulls on the tension member 140 to unhook the latch 136. The continued upward swinging movement of the lift arm pulls farther on the tension member 140 to swing the treatment unit 85 up away from the upper carriage, as shown at 140' in FIG. 5. This upward swinging of the treatment unit away from the upper carriage facilitates removal of the belt In installations in which a predetermined fixed downward inclination of the casting region C is desired, the main chassis frame 24 can be rigidly attached to the U- shaped base unit B. A three point support for the machine as a whole is then provided by using three foot pads. Two of these foot pads are then located beneath the outboard ends of the respective base beams 34 and 36, i.e. beneath the two arms of the U-shaped base. The third foot pad is then located beneath the center of the 'back of the base frame 26.

We claim:

1. A carriage orientation and lift system for a twinbelt continuous metal casting machine comprising:

a machine frame including a chassis with a back frame extending upwardly therefrom,

a lower belt carriage extending outboard from this chassis in rigid cantilevered relationship adapted to have a lower casting belt revolved around it,

a fulcrum pivot on said back frame above the level of said lower carriage,

a lift arm pivotally attached to said back frame by said fulcrum pivot, said lift arm having a rear portion extending behind said back frame and a front portion extendingin front of said back frame,

lift means connected to the rear portion of said lift arm and to the frame for pulling downwardly on the rear portion of said lift arm to swing up the front portion thereof,

an upper carriage connected by a pivot assembly to the front portion of said lift arm, said upper carriage being positioned above said lower carriage and being adapted to have an upper casting belt revolved around it in parallel relationship with said lower belt,

a convex circularly curved cylindrical segment positioned on said back frame at a lower level than said fulcrum pivot,

roller means mounted on said upper carriage at a lower level than said pivot assembly in rolling engagement with said curved cylindrical segment,

the axis of said curved cylindrical segment being parallel with the axis-of said pivot assembly and also parallel with the axis of said fulcrum pivot,

the distance from said fulcrum pivot to the axis of said curved cylindrical segment being equal to the distance from the axis of said pivot assembly to the axis of said roller means, and

the effective radius of curvature of said curved cylindrical segment plus the radius of said roller means being equal to the distance between the axis of said fulcrum pivot and the axis of said pivot assembly,

thereby to maintain the upper carriage parallel with the lower carriage as the upper carriage is raised and lowered by said lift arm.

2. A carriage orientation and lift system for a twinbelt continuous metal casting machine as claimed in claim 1, in which said upper carriage has an L-shaped structure as seen in cross section formed by an upright frame portion connected by said pivot assembly to said lift arm and an outboard extending cantilevered por tion around which said upper belt is revolved, with said roller means being mounted on said upper carriage near the elbow of said L-shaped structure.

3. A carriage orientation and lift system for a twinbelt continuous metal casting machine as claimed in claim 1, in which said pivot assembly connecting the upper carriage to the forward portion of said lift arm includes means for shifting the upper carriage in the upstream and downstream direction parallel with the axis of said pivot assembly, and said curved cylindrical segment extends upstream and downstream along said back frame sufficiently for it to be engaged by said roller means at all upstream and downstream shifted positions of said upper carriage.

4; A carriage orientation and lift system for a twinbelt continuous metal casting machine as claimed in claim 3, in which said pivot assembly includes first, second and third axially spaced hanger members on the forward portion of said lift arm, a tubular member slidably mounted in said hanger members, a pair of axially spaced support members secured to said upper carriage, one of said support members being secured to said tubular member between the first and second hanger member and the other of said support members being secured to said tubular member between the second and third hanger member for providing firm support for the upper carriage at all of its shifted positions.

5. A carriage orientation and lift system for a twinbelt continuous metal casting machine as claimed in claim 1, in which a tangent plane to said convex circularly curved cylindrical segment near the center of the operating range of said roller means extends vertically, whereby a relatively large amount of lift of the upper carriage is provided with a minimum amount of lateral displacement thereof.

6. A carriage orientation and lift system for a twinbelt continuous metal casting machine as claimed in claim 1, in which said fulcrum (pivot comprises two pivot assemblies at the upstream and downstream side of said lift arm, each of said pivot assemblies including a pivot pin projecting out from the side of said lift arm, a pair of upstanding support members on the upstream and downstream side of said back frame, respectively, and an eccentric bushing mounted in each of said support members, said eccentric bushings each being rotatable about the pivot pin and lockable in different positions for adjusting the lift arm to adjust the upstream and downstream ends of said upper carriage vertically and laterally to align the upper belt to track along the casting region precisely parallel with the lower belt, thereby to avoid lateral creeping movement between the belts and metal section being cast.

7. A carriage orientation and lift system for a twinbelt continuous metal casting machine as claimed in claim 1, in which a platform extends rearwardly from said chassis frame in cantilevered relationship therefrom, and the drive mechanism for revolving the belts on said carriages is mounted on said platform.

8. A carriage orientation and lift system for a twinbelt continuous metal casting machine as claimed in claim 1, including a base support unit having a pair of spaced parallel beams extending outboard beneath the lower carriage and a base frame extending between said beams and positioned beneath said main chassis frame, said main chassis frame being pivotally connected to said base frame at the downstream end of said machine by a front and rear pivot which are axially aligned, and means for adjusting the elevation of the upstream end of said main chassis frame.

9. A carriage orientation and lift system for a twinbelt continuous metal casting machine as claimed in claim 8, including hold down clamp means for preloading the chassis frame down against the base frame at said rear pivot.

10. A carriage orientation and lift system for a twinbelt continuous metal casting machine as claimed in claim 1, in which an upwardly extending safety link is pivotally connected to the front of the upstanding back frame, said safety link being swingable forward into an extended position, said upper carriage has a ledge on its inboard side under which the extended safety link can be engaged when said carriage is in its raised position, and said ledge extending upstream and downstream a sufficient distance to be engageable by the extended safety link regardless of whether the upper carriage is in its upstream or downstream position.

11. A carriage orientation and lift system for a twinbelt continuous metal casting machine as claimed in claim 5, in which said lift arm extends generally horizontally in the mid-range of its lift travel and said lift means act downwardly and forwardly on the rear portion of said lift arm to provide an approximately constant mechanical advantage throughout the range of lift operation, whereby a substantially constant fluid pressure can be used in said lift cylinder means throughout said range of operation.

12. A carriage orientation and lift system for a twinbelt continuous metal casting machine as claimed in claim 5, in which the hardness of the curved surface of said curved cylindrical segment is less than the hardness of the roller means engaged thereagainst.

13. A carriage orientation and lift system for a twinbelt continuous metal casting machine as claimed in claim 1, in which a belt treatment unit extends across the upper carriage from its inboard side to its outboard side, latch means on the outboard side of said treatment unit for latching said unit to the upper carriage in operating position, a tension member connected to the front end of said lift amt above the level of said pivot assembly and being connected to said latch means, whereby the initial part of the upward swing of the front portion of said lift arm will pull said tension member to unlatch said latch means, and the farther upward swing of said lift arm will pull said tension member farther to swing saidtreatment unit up away from the upper carriage.

14. A carriage orientation and lift system for a twinbelt continuous metal casting machine as claimed in claim 1, including a base support unit having a pair of spaced parallel beams extending outboard beneath the lower carriage and a base frame extending between said beams and positioned beneath said main chassis frame, each of said beams having a foot pad beneath its outboard end engageable with the ground, and said base frame having a third foot pad located beneath it intermediate said beams and engageable with the ground, whereby the machine as a whole has a three point support.

15. A carriage orientation and lift system for a twinbelt continuous metal casting machine comprising:

a machine frame including a chassis with a back frame extending upwardly therefrom,

a lower belt carriage extending outboard from this chassis in rigid cantilevered relationship adapted to have a lower casting belt revolved around it,

fulcrum pivot means mounted on said back frame above the level of said lower carriage,

a lift arm pivotally attached to said back frame by said fulcrum pivot means, said lift arm having a rear portion extending behind said back frame and a front portion extending in front of said back frame,

lift means connected to the rear portion of said lift arm and to the frame for pulling downwardly on the rear portion of said lift arm to swing up the front portion thereof,

an upper carriage connected by a pivot assembly to the front portion of said lift arm, said upper carriage being positioned above said lower carriage and being adapted to have an upper casting belt revolved around it in parallel relationship with said lower belt,

a' convex cylindrical member positioned on said back frame at a lower level than said fulcrum pivot,

roller means mounted on said upper carriage at a lower level than said pivot assembly in rolling engagement with said cylindrical member,

said cylindrical member extending parallel with the axis of said pivot assembly and also parallel with said fulcrum pivot means, and

said fulcrum pivot means comprising two axially aligned spaced pivot mechanisms, at least one of said pivot mechanisms including adjustment means for slightly shifting the effective position of one of said pivot mechanisms relative to the other pivot mechanism,

thereby slightly to shift the orientation of the lift arm and upper carriage with respect to the lower carriage for tracking the movement of the upper belt with respect to the lower belt along the top and bottom of the casting region defined between said belts to avoid lateral creeping movement of the belts with respect to the product being cast between them. 

1. A carriage orientation and lift system for a twin-belt continuous metal casting machine comprising: a machine frame including a chassis with a back frame extending upwardly therefrom, a lower belt carriage extending outboard from this chassis in rigid cantilevered relationship adapted to have a lower casting belt revolved around it, a fulcrum pivot on said back frame above the level of said lower carriage, a lift arm pivotally attached to said back frame by said fulcrum pivot, said lift arm having a rear portion extending behind said back frame and a front portion extending in front of said back frame, lift means connected to the rear portion of said lift arm and to the frame for pulling downwardly on the rear portion of said lift arm to swing up the front portion thereof, an upper carriage connected by a pivot assembly to the front portion of said lift arm, said upper carriage being positioned above said lower carriage and being adapted to have an upper casting belt revolved around it in parallel relationship with said lower belt, a convex circularly curved cylindrical segment positioned on said back frame at a lower level than said fulcrum pivot, roller means mounted on said upper carriage at a lower level than said pivot assembly in rolling engagement with said curved cylindrical segment, the axis of said curved cylindrical segment being parallel with the axis of said pivot assembly and also parallel with the axis of said fulcrum pivot, the distance from said fulcrum pivot to the axis of said curved cylindrical segment being equal to the distance from the axis of said pivot assembly to the axis of said roller means, and the effective radius of curvature of said curved cylindrical segment plus the radius of said roller means being equal to the distance between the axis of said fulcrum pivot and the axis of said pivot assembly, thereby to maintain the upper carriage parallel with the lower carriage as the upper carriage is raised and lowered by said lift arm.
 2. A carriage orientation and lift system for a twin-belt continuous metal casting machine as claimed in claim 1, in which said upper carriage has an L-shaped structure as seen in cross section formed by an upright frame portioN connected by said pivot assembly to said lift arm and an outboard extending cantilevered portion around which said upper belt is revolved, with said roller means being mounted on said upper carriage near the elbow of said L-shaped structure.
 3. A carriage orientation and lift system for a twin-belt continuous metal casting machine as claimed in claim 1, in which said pivot assembly connecting the upper carriage to the forward portion of said lift arm includes means for shifting the upper carriage in the upstream and downstream direction parallel with the axis of said pivot assembly, and said curved cylindrical segment extends upstream and downstream along said back frame sufficiently for it to be engaged by said roller means at all upstream and downstream shifted positions of said upper carriage.
 4. A carriage orientation and lift system for a twin-belt continuous metal casting machine as claimed in claim 3, in which said pivot assembly includes first, second and third axially spaced hanger members on the forward portion of said lift arm, a tubular member slidably mounted in said hanger members, a pair of axially spaced support members secured to said upper carriage, one of said support members being secured to said tubular member between the first and second hanger member and the other of said support members being secured to said tubular member between the second and third hanger member for providing firm support for the upper carriage at all of its shifted positions.
 5. A carriage orientation and lift system for a twin-belt continuous metal casting machine as claimed in claim 1, in which a tangent plane to said convex circularly curved cylindrical segment near the center of the operating range of said roller means extends vertically, whereby a relatively large amount of lift of the upper carriage is provided with a minimum amount of lateral displacement thereof.
 6. A carriage orientation and lift system for a twin-belt continuous metal casting machine as claimed in claim 1, in which said fulcrum pivot comprises two pivot assemblies at the upstream and downstream side of said lift arm, each of said pivot assemblies including a pivot pin projecting out from the side of said lift arm, a pair of upstanding support members on the upstream and downstream side of said back frame, respectively, and an eccentric bushing mounted in each of said support members, said eccentric bushings each being rotatable about the pivot pin and lockable in different positions for adjusting the lift arm to adjust the upstream and downstream ends of said upper carriage vertically and laterally to align the upper belt to track along the casting region precisely parallel with the lower belt, thereby to avoid lateral creeping movement between the belts and metal section being cast.
 7. A carriage orientation and lift system for a twin-belt continuous metal casting machine as claimed in claim 1, in which a platform extends rearwardly from said chassis frame in cantilevered relationship therefrom, and the drive mechanism for revolving the belts on said carriages is mounted on said platform.
 8. A carriage orientation and lift system for a twin-belt continuous metal casting machine as claimed in claim 1, including a base support unit having a pair of spaced parallel beams extending outboard beneath the lower carriage and a base frame extending between said beams and positioned beneath said main chassis frame, said main chassis frame being pivotally connected to said base frame at the downstream end of said machine by a front and rear pivot which are axially aligned, and means for adjusting the elevation of the upstream end of said main chassis frame.
 9. A carriage orientation and lift system for a twin-belt continuous metal casting machine as claimed in claim 8, including hold down clamp means for pre-loading the chassis frame down against the base frame at said rear pivot.
 10. A carriage orientation and lift system for a twin-belt continuous metal casting machine as claimed in cLaim 1, in which an upwardly extending safety link is pivotally connected to the front of the upstanding back frame, said safety link being swingable forward into an extended position, said upper carriage has a ledge on its inboard side under which the extended safety link can be engaged when said carriage is in its raised position, and said ledge extending upstream and downstream a sufficient distance to be engageable by the extended safety link regardless of whether the upper carriage is in its upstream or downstream position.
 11. A carriage orientation and lift system for a twin-belt continuous metal casting machine as claimed in claim 5, in which said lift arm extends generally horizontally in the mid-range of its lift travel and said lift means act downwardly and forwardly on the rear portion of said lift arm to provide an approximately constant mechanical advantage throughout the range of lift operation, whereby a substantially constant fluid pressure can be used in said lift cylinder means throughout said range of operation.
 12. A carriage orientation and lift system for a twin-belt continuous metal casting machine as claimed in claim 5, in which the hardness of the curved surface of said curved cylindrical segment is less than the hardness of the roller means engaged thereagainst.
 13. A carriage orientation and lift system for a twin-belt continuous metal casting machine as claimed in claim 1, in which a belt treatment unit extends across the upper carriage from its inboard side to its outboard side, latch means on the outboard side of said treatment unit for latching said unit to the upper carriage in operating position, a tension member connected to the front end of said lift arm above the level of said pivot assembly and being connected to said latch means, whereby the initial part of the upward swing of the front portion of said lift arm will pull said tension member to unlatch said latch means, and the farther upward swing of said lift arm will pull said tension member farther to swing said treatment unit up away from the upper carriage.
 14. A carriage orientation and lift system for a twin-belt continuous metal casting machine as claimed in claim 1, including a base support unit having a pair of spaced parallel beams extending outboard beneath the lower carriage and a base frame extending between said beams and positioned beneath said main chassis frame, each of said beams having a foot pad beneath its outboard end engageable with the ground, and said base frame having a third foot pad located beneath it intermediate said beams and engageable with the ground, whereby the machine as a whole has a three point support.
 15. A carriage orientation and lift system for a twin-belt continuous metal casting machine comprising: a machine frame including a chassis with a back frame extending upwardly therefrom, a lower belt carriage extending outboard from this chassis in rigid cantilevered relationship adapted to have a lower casting belt revolved around it, fulcrum pivot means mounted on said back frame above the level of said lower carriage, a lift arm pivotally attached to said back frame by said fulcrum pivot means, said lift arm having a rear portion extending behind said back frame and a front portion extending in front of said back frame, lift means connected to the rear portion of said lift arm and to the frame for pulling downwardly on the rear portion of said lift arm to swing up the front portion thereof, an upper carriage connected by a pivot assembly to the front portion of said lift arm, said upper carriage being positioned above said lower carriage and being adapted to have an upper casting belt revolved around it in parallel relationship with said lower belt, a convex cylindrical member positioned on said back frame at a lower level than said fulcrum pivot, roller means mounted on said upper carriage at a lower level than said pivot assembly in rolling engagement with said cylindrical member, saiD cylindrical member extending parallel with the axis of said pivot assembly and also parallel with said fulcrum pivot means, and said fulcrum pivot means comprising two axially aligned spaced pivot mechanisms, at least one of said pivot mechanisms including adjustment means for slightly shifting the effective position of one of said pivot mechanisms relative to the other pivot mechanism, thereby slightly to shift the orientation of the lift arm and upper carriage with respect to the lower carriage for tracking the movement of the upper belt with respect to the lower belt along the top and bottom of the casting region defined between said belts to avoid lateral creeping movement of the belts with respect to the product being cast between them. 